IsoCubeSim is my cuboid (LxMxN) simulator, but I've made a few variations which do other things. It was specifically designed to be used for computer speedcubing - before the era of more complex keyboard-controlled cube sims, many of the world speed records were set on this program. IsoCubeSim and IsoSupercubeSim have the following features (the others are a bit older):

IsoCubeSim is distributed as a self-executable .jar file. You should be able to run it like an application, if you have Java installed. Because a certain browser doesn't handle .jar files correctly, I've included each one in a .zip file. Here are the versions available for download: